EP0090233B1 - Device for cleaning a welding torch - Google Patents

Description

The invention relates to a device for cleaning a welding torch which has a central contact nozzle and a tubular gas nozzle surrounding the contact nozzle at a distance, with a rotatably mounted cleaning head which can be driven in the direction of rotation, which is provided with at least one clearing member and with a cleaning head opposite it, coaxially therewith arranged nozzle holder into which the welding torch to be cleaned can be inserted.

An arrangement of this type is known from DE-A 29 43 650. This known device does indeed allow mechanical removal of metal splashes which contaminate the intermediate space between the contact nozzle and the gas nozzle. However, the known device does not provide any means for applying a so-called non-stick agent which is intended to counteract rapid contamination. If a non-stick agent counteracting contamination is used, it is therefore necessary in the known device to apply this non-stick agent manually. However, this can not only prove to be very cumbersome and time-consuming, but can also have a negative impact on the consumption of non-stick agents.

Proceeding from this, it is therefore the object of the present invention to improve a device of the generic type in such a way that not only removal of metal splashes, but also simple application of an anti-adhesive agent is possible.

This object is achieved according to the invention in that, in addition to the cleaning head provided with at least one clearing member, a spray head is provided opposite an associated nozzle holder into which the welding torch can be inserted and which has a spray nozzle which can be acted upon with an anti-adhesive agent and which at the outlet of a suction side on a Tank for non-stick suction device is connected, which has a flow pump operable with welding gas.

These measures advantageously result in a fusion of a non-stick agent spraying device and a cleaning device into a compact device, which not only ensures a high level of user-friendliness, but also a high degree of reliability, since, as a result of the integration of the non-stick agent application device in the cleaning device, also a reliable machine application guaranteed by non-stick agents. At the same time, the measures according to the invention result in an automatic and at the same time economical metering of the anti-adhesive. Because the back pressure that builds up in a corresponding gas supply line when the line is shut off drops very quickly when the line is opened, and since the normal gas flow in the gas supply line is not sufficient for the Venturi effect, there is advantageously only a short spray burst, so that an automatic termination the spraying process and an economical dosage of non-stick agents are guaranteed. Another advantage of the measures according to the invention can be seen in the fact that practically every effort to provide a fluid source assigned to the spray head is eliminated, since a welding gas source is available in every welding operation. The advantages that can be achieved with the invention can thus be seen in particular in excellent ease of use and reliability and thus overall in good economy.

In an expedient further development of the superordinate measures, two nozzle holders arranged next to one another can be provided for inserting a welding torch, one of which is opposite a spray head and one is opposite a cleaning head. This advantageously results in a particularly clear structure and a particularly obvious mode of operation.

A further expedient measure can consist in that the cleaning head and / or the spray head can be activated by means of a respectively associated contact switch, which is arranged in the area of the assigned, preferably removable or exchangeable, nozzle contact and can be actuated by a welding torch inserted into the relevant nozzle holder . These measures can advantageously greatly simplify handling, since the contact switches automatically activate or passivate the cleaning or spray head.

A further advantageous embodiment of the superordinate measures can consist in that at least one spring pin which is arranged eccentrically with respect to the axis of rotation of the cleaning head and which preferably has a shape adapted to the contour of the assigned surface can be provided as the clearing member. This spring pin can be plugged directly onto the cleaning head or can be picked up by a spiral spring. Such a spring pin can yield in an advantageous manner when resistance occurs, which means that the surfaces to be cleaned should be treated gently. The spring pin engaging in an annular space between two surfaces to be cleaned is excited to vibrate when it hits impurities, so that excellent cleaning of both the inner surface of the gas nozzle and the outer surface of the contact nozzle can be achieved with the aid of only one spring pin. If a spiral spring is used, this is further aggravated by the scraper movements of the clearing member caused thereby. On the other hand, when using spring pins that are plugged directly onto the cleaning head, it is ensured that the contaminants removed thereby bounce off the cleaning head unhindered and can be thrown off by the latter.

In the device known from DE-A-29 43 650, the clearing member also has a spring pin. However, this is not adapted to the contour of the surfaces to be cleaned, but should run parallel to the axis. Apart from this, in the known device not only should the axially parallel spring pin penetrate into the space between the gas nozzle and the contact nozzle, but also the spiral spring carrying the pin here. The elastic properties of this spiral spring therefore do not come into play here, or at least not to any significant extent. In the known arrangement, it is therefore necessary to resiliently suspend the motor receiving the cleaning head, but this can lead to a high outlay.

Further expedient refinements and advantageous developments of the superordinate measures are characterized in further dependent claims.

• Figur 1 eine Ansicht eines als Tischgerät ausgebildeten Ausführungsbeispiels,
• Figur 2 einen durch die dem Reinigungskopf zugeordnete Düsenfassung verlaufenden Schnitt durch das Gerät nach Figur 1,
• Figur 3 eine Ansicht eines mit einer Spiralfeder bestückten Reinigungskopfes,
• Figur 4 eine Ansicht eines mit zwei Federstiften versehenen Reinigungskopfes und
• Figur 5 einen durch die dem Sprühkopf zugeordnete Fassung verlaufenden Schnitt durch das Gerät nach Figur 1.

An exemplary embodiment of the invention is explained in more detail below with reference to the drawing. The drawing shows:

• FIG. 1 shows a view of an exemplary embodiment designed as a table device,
• FIG. 2 shows a section through the device according to FIG. 1 through the nozzle holder assigned to the cleaning head,
• FIG. 3 shows a view of a cleaning head equipped with a spiral spring,
• Figure 4 is a view of a cleaning head provided with two spring pins and
• 5 shows a section through the device assigned to the spray head through the device according to FIG. 1.

The table device shown in FIG. 1 is provided with a self-supporting housing 1, preferably made of sheet metal, which can be fixed on a suitable table top with the aid of retaining screws 2. In the area of the operating side, a wall section 3 inclined in a desk-like manner to achieve good accessibility and good visibility is provided, which has the nozzle holders for inserting the welding torch to be cleaned or to be treated with an anti-adhesive agent. In the exemplary embodiment shown, two nozzle holders 4 and 5 arranged next to one another are provided. One nozzle holder 4 leads to a cleaning head 6 opposite it, the other nozzle holder 5 leads to a spray head 7 lying opposite it. The cleaning head 6 serves to remove metal splashes which are deposited in the front region of a welding torch, the spray head 7 serves to spray in the cleaned surfaces of a welding torch with a non-stick agent that counteracts deposits of metal splashes. The structure and mode of operation of an inert gas welding torch are known per se and therefore do not require any extensive explanation in the present context. Such a welding torch consists, as can be seen from FIGS. 2 and 3, of a contact nozzle 8 guiding the welding wire during welding and a tubular gas nozzle 9 surrounding it at a distance, the protective gas carrying the protective gas. The gas nozzle 9 is bundled in the region of its front end the gas flow conically constricted. The contact nozzle 8, with which the current is transmitted to the welding wire, is provided in the region of its front end with a truncated cone which is approximately parallel to the constriction of the gas nozzle 9. The welding torch to be cleaned or sprayed is inserted into the nozzle holder 4 or 5 until it stops.

As shown in FIG. 2 with the aid of the nozzle holder 4, the nozzle holders 4 and 5 can be provided with an inlet cone 10 which facilitates the insertion of a welding torch. As can further be seen in FIG. 2, the nozzle holder 4 assigned to the cleaning head 6 consists of a ring 11 which is fixed on the wall section 3 and has the inlet cone 10 and onto which a retaining bush 12 which engages in the housing 1 and faces the cleaning head 6 is formed. The diameter of the sleeve bore is slightly oversized compared to the outside diameter of the gas nozzle 9 of an associated welding torch, so that the welding torch to be cleaned can be inserted or carried out freely. The nozzle holder 4 and the associated cleaning head 6 are arranged coaxially one behind the other in the axial direction. The cleaning head 6 is equipped with a broaching element which engages in the facing holding sleeve 12 and, when the welding torch is inserted, in the annular space 13 between the contact nozzle 8 and the gas nozzle 9. To drive the rotatably mounted cleaning head 6 in the direction of rotation, a motor 15 is provided on the housing 1 and is arranged coaxially to the axis of the nozzle holder 4. In the exemplary embodiment shown, the housing 1 for receiving the motor 15 is provided with an intermediate wall 16 arranged approximately perpendicular to the axis of the nozzle holder 4 or associated cleaning head 6 or drive shaft 14. The housing 1 is so elongated in the direction of the axis a, which extends approximately perpendicular to the wall section 3 inclined like a desk, that the nozzle holder 4, the cleaning head 6 and the associated drive motor 15 find space one behind the other.

The cleaning head 6 is simply designed as a component which can be plugged onto the motor shaft 14 and is secured in the direction of rotation and in the axial direction. For this purpose, a driving screw 17 engaging in a recess of the drive shaft 14 can be provided. The driver screw 17 is easily detachable, so that the cleaning head 6 can be easily removed and exchanged for another. A set with a plurality of cleaning heads 6 can expediently be provided, the clearing element of which is adapted to different nozzle types and which are therefore replaced as required. The same also applies to the nozzle holders 4 and 5, the bores of which are also adapted to a respective nozzle type. To activate the An drive motor 15, a contact switch 18 which can be actuated by the welding torch inserted into the nozzle holder 6 is provided in FIG. This is simply provided with a switching pin 19 which, with a roller arranged thereon, reaches through a slot in the holding sleeve 12. The contact switch for activating the drive motor 15 could also simply be designed as a spiral spring or the like that extends through the slot of the holding bush 12 with a crank.

In the exemplary embodiment shown in FIG. 2, the cleaning head 6 is equipped with two pivotably mounted clearing vanes 20 and 21 to form the clearing member, one of which clearing vanes 20 the front end of the contact nozzle 8 and the other clearing wing 21 the front end of the inner circumference of the gas nozzle 9 should clean. The cleaning head 6 is designed to receive the pivotable clearing blades 20 and 21 in the region of its front end in a fork shape. The clearing vanes 20 and 21 are designed and arranged in such a way that, under the action of the centrifugal forces acting on them while the motor is running, they pivot in opposite directions radially inwards or outwards, so that their preferably rounded edges fit against the respectively assigned, cleaned outer surface . In order to accomplish a clean cleaning process, the clearing edges of the clearing blades 20 and 21 are chamfered approximately parallel to the cross-sectional profile of the respectively assigned outer surface. The clearing wing 20 pivoting inward under the action of centrifugal force is connected in the manner of a two-armed lever to a counterweight 22 which commonly extends thereto and is coupled by means of a spring 23 to the adjacent clearing wing 21 without counterweight. Instead of one or more swiveling clearing vanes, bristles of a steel brush or the like could also be provided to form the clearing member.

In the embodiment on which FIG. 3 is based, the cleaning head, also denoted here by 6, is equipped with a spiral spring 24 arranged coaxially to the axis a, the foremost turn of which, facing away from the cleaning head 6, ends in a bent spring pin 25 which is eccentric with respect to the axis a and which Forming organ and engages in the annular space 13 between the contact nozzle 8 and gas nozzle 9. The spring pin 25 practically formed here by an end section of the spring wire has a round cross section, which results in a particularly gentle treatment of the outer surfaces to be cleaned. The spiral spring 25 enables wobbling movements of the spring pin 25 forming the broaching element while the drive motor is running, so that it comes into cleaning contact both with the inner circumferential surface of the gas nozzle 9 and with the outer circumferential surface of the contact nozzle 8. The spring pin 25 is bent approximately parallel to the course of the adjacent lateral surfaces. Instead of a spring pin 25 that runs out of the spring 24 and is practically molded onto it, a pin that forms the cleaning element and is attached to the spring 24 could also be provided.

In the exemplary embodiment on which FIG. 4 is based, two spring pins 36 and 37 are simply provided to form broaching elements, which can be inserted into assigned, eccentric bores of the cleaning head 6 and can be clamped by means of clamping screws 38 extending perpendicularly thereto. The spring pin 36 shown on the left in FIG. 1 is to be assigned to the inner surface of the gas nozzle 9 in the exemplary embodiment shown. The other spring pin 37 should be assigned to the outer surface of the contact nozzle 8. The spring pins 36 and 37 consist of round steel and are adapted to the contour of the respectively assigned surface. The spring pin assigned to the gas nozzle 9 is provided above the cleaning head 6 with a radially outward offset 39 which represents a cleaning edge for the end face of the gas nozzle 9 and at the same time can form a stop. The fact that the spring pins 36 and 37 are placed here directly on the cleaning head 38, in contrast to the use of a spiral spring, which can act as a collecting container, results in a simple and unobstructed execution of dirt. In the illustrated embodiment, the spring pins 36 and 37 are inserted into the holes in the cleaning head 6. But it would also be conceivable to clamp the spring pin or pins on the cleaning head 6. In the case of two spring pins, as here, a bracket which can be fixed on the cleaning head 6 and has an approximately U-shaped cross section could be provided, the legs of which form the spring pins. In any case, the spring pins can be exchanged, so that the appropriate spring pin (s) can be used for each welding torch to be cleaned.

After mechanical cleaning, the cleaned outer surfaces are sprayed with a non-stick agent. If the spray head required for this is arranged in the area of the cleaning head, only a nozzle holder is required. In the exemplary embodiment shown, as shown in FIG. 1, two nozzle holders arranged next to one another are provided, of which the nozzle holder 4 is loaded during cleaning and the nozzle holder 5 when sprayed. The nozzle holder 5 assigned to the spray head 7 can, as can be seen best in FIG. 5, be designed as a pipe section which can be fastened by means of a spacer lug 26 to the wall section 3 above a wall recess 27, the edges of which form a spray backdrop. The spray head 7 is provided with a spray nozzle 28 arranged coaxially to the axis of the associated nozzle holder 5, the nozzle opening of which is located somewhat within the wall section 3, so that the edges of the assigned wall recess 27 act as a backdrop, which prevent the spray jet from being scattered too much. A suction device is provided to act upon the spray nozzle 28 with the liquid non-stick agent hen that is on the suction side of a corresponding tank.

In the illustrated embodiment, a flow pump is provided to form the suction device. For this purpose, the spray nozzle 28 is arranged at the outlet of a Venturi nozzle 29 which is provided with a fluid connection and which has a suction nozzle 31 inserted into a non-stick agent tank 30. The tank 30 is arranged here in the housing 1 and secured in its position by clamping springs 32. In order to achieve easy access to the tank 30 and / or to the drive motor 15 arranged next to it and assigned to the cleaning head, the housing 1 is provided with a removable cover.

The activation of the Venturi nozzle 29, i.e. the application of fluid, is accomplished by means of a contact switch 34 which can be actuated by the burner inserted into the associated nozzle holder. In the exemplary embodiment shown, the contact switch 34 is provided with a swivel lever 35 which also acts as a burner stop and which engages a switching pin. The stop position of the pivot lever 35 and the associated switching pin can be adjusted by means of the associated set screws.

Welding gas, which is taken from a corresponding gas source, is used as the fluid for sucking and spraying the non-stick agent, which results in a particularly simple design, since welding gas is available in every welding shop. In the present case, it is a protective gas that normally contains the components argon and CO ₂ . Such a gas mixture can be safely used as a fluid for acting on the flow pump provided here. In the case of a central gas supply, a branch line 33 leading to the Venturi nozzle 29 is simply branched off from this. Normally, however, a gas bottle is assigned to each welding apparatus or welding torch, an example of this is based on FIG. 5. Here, the gas line 41 leading from the gas bottle 40 to the associated welding torch is provided with a T-piece 42, the branch outlet 43 of which is located at the entrance of the Venturi nozzle 29 by means of the branch line 33. The provision of the fluid required to activate the Venturi nozzle 29 obviously does not require any significant additional effort. The gas throughput for welding operation is adjustable by means of an adjusting element 44. The throughput of inert gas welding torches is in the order of about 10 liters per minute. If no more gas is consumed, a certain dynamic pressure builds up in the line system downstream of the setting element 44, which drops relatively quickly when the gas is subsequently removed. This advantageously results in an automatic termination of the spraying process for the spraying process following an initial spraying burst, since the normal gas flow is not sufficient for the Venturi effect. This ensures economical consumption and automatic dosing of the non-stick agent.

Claims (7)

1. A device for cleaning a welding torch with a central nozzle (8) and a tube-like gas nozzle (9) surrounding the said contact nozzle (8) at a distance, having a cleaning head (6) which is turningly supported, can be driven in the direction of turning, and has at least one clearing organ (20, 21 or resp. 25 or resp. 36, 37), and a nozzle holder (4) which is situated opposite the cleaning head (6) and coaxial therewith and into which the blowpipe to be cleaned can be inserted, characterized in that, beside the cleaning head (6), there is a spraying head (7) situated opposite the nozzle holder (4) or opposite a second nozzle holder (5), into which another blowpipe can be inserted, and having a spraying nozzle (28) which can be charged with an anti-adhesive agent and is connected with the outlet of a sucking mechanism connected with the sucking side to a tank (3) for an anti-adhesive agent and having a flow pump (29) which can be operated on welding gas.

2. A device as claimed in claim 1 characterized in that the flow pump (29) is connected with the branch piece (43) of a T-piece (42) situated in a gas pipe which comes from a gas source and preferably has a pressure-reducing valve (44).

3. A device as claimed in anyone of the preceding claims characterized in that the cleaning head (6) and/or the spraying head (7) can be activated by means of a contact switch (18 or resp. 19) which can be operated by a welding torch inserted into the respective nozzle holder (4 or resp. 5).

4. A device as claimed in anyone of the preced- . ing claims characterized in that, as a clearing organ, there ist at least one spring pin (25 or resp. 36, 37) which is eccentric in relation to the turing axis of the cleaning head (6), can preferably be put onto the cleaning head (6), and is preferably shaped according to the contour of the cooperating surface.

5. A device as claimed in claim 4 characterized in that there are two clearing pins (36 or resp. 37) which are preferably situated opposite each other and of which one cooperates with the gas nozzle (9) and one with the contact nozzle (8) whereby preferably at least the spring pin (36) cooperating with the inner circumference of a gas nozzle (9) of a protective gas welding torch has a crank (39) which comes to rest against the cooperating front side of the nozzle.

6. A device as claimed in anyone of the preceding claims characterized in that the cleaning head (6) has at least one clearing wing (20 or resp. 21) which is turningly supported, forms the clearing organ, and of which the edges preferably in the form of rounded-off clearing edges are curved according to the respective cooperating surface to be cleaned.

7. A device as claimed in claim 6 characterized in that there are two clearing wings (20 or resp. 21) which take action in the annular area between the gas nozzle (9) and the contact nozzle (8), turn in contrary sense due to the effect of the centrifugal force, and of which one cooperates with the outer circumference of the contact nozzle (8) and one with the inner circumference of the gas nozzle (9).

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